Centrifugal casting machine



July 18, 1961 H. R. BERGER 2,992,463

CENTRIFUGAL CASTING MACHINE IN VEN TOR.

A TTORNEYS July 18, 1961 H. R. BERGER 2,992,463

CENTRIFUGAL CASTING MACHINE Filed March 5, 1959 2 Sheets-Sheet 2 A MJNVENToR. @i o /rfr e/yer f BY @MM b TTONEKS United States iPatent2,992,463 CENTRIFUGAL CASIHNG MACHINE Herbert R. Berger, Bethel, Conn.,assignor to J. F. Jelenlro 8: Co., Inc., 'New York, N.Y., `a corporationof New York Filed Mar. 5, 1959, Ser. No. 797,522 3 Claims. (Cl.`22-6S.1)

This invention relates to centrifugal casting machines.

The primary object of the present invention is the provision of acentrifugal casting machine which is operable to produce metal castingsof improved quality, especially in respect to the uniformity of densityof each casting. Pursuant to this object of the invention, the mold orflask into which the molten metal is forciblyinjected from the furnaceby centrifugal action is rotated about its own longitudinal axis whichextends radially of or at right angles to 'the axis about which thefurnace is rotated during the centrifugal casting operation. As a resultof this rotation of the mold or flask into which the molten metal isintroduced by the centrifugal action, the metal flows under pressureagainst successive wall portions or increments of the mold, therebyobviating uneven distribution of the metal in the mold and unevenpressure on the metal in different parts of the mold cavity.

The above and other objects, features and advantages of the presentinvention will be fully understood from the following descriptionconsidered in connection with the accompanying illustrative drawings.

In the drawings:

FIG. l is a top plan view of a centrifugal casting machine embodying thepresent invention;

FIG. 2 is a view, on a larger scale, partly in velevation and partly insection on the line 2 2 of FIG. l;

FIGS. 3, 4 and 5 are vertical sectional views on the lines 3 3, ri--dand 5--5, respectively, of FIG. 2;

FIG. 6 is a fragmentary horizontal plan view, partly in section, on theline 6-6 of FlG. 2;

FIG. 7 is a fragmentary sectional View, on a larger scale, on the line7-7 of FIG. 6;

FIG. 8 is a fragmentary side elevational view showing another form ofthe invention;

FIG. 9 is a vertical sectional view on the line 9-9 `of FIG. 8;

FIG. l is a horizontal View, partly in section, on the line iti-l0 ofFIG. 8;

FlG. ll is a vertical sectional view of the flask and a companionremovable auxiliary device utilized when forming the mold cavity in theflask; and

FIG. l2 is a top plan View of said auxiliary device.

Referring now to the drawings in detail, the centrifugal casting machineis preferably of the construction illustratecl and described in UnitedStates Patent No. 2,752,650, issued to 'the assignee of my presentapplication, but it will be understood that the present invention is notlimited in its application to a centrifugal casting machine of thespecific construction or operation disclosed in said patent. Brieflydescribed, the centrifugal casting machine includes an electricallyheated furnace l0 which is fixed to a bar l2 which is rotated by theshaft i4 of a spring motor M. More particularly, the intermediate or hubportion 16 of said bar is connected for rotation to said shaft 14 by atransverse pin i8 fixed to said shaft and releasably engaging hubportion 16 in a notch 19, and a removable clamping screw 2G is threadedon the upper end portion of the shaft and engages the hub i6 of the barfor releasably holding said bar securely connected to the shaft. Thefurnace lil is preferably provided with a carbon crucible 22 of the typeshown by my United States Patent No. 2,375,463. 4Said Crucible isprovided with a sprue 24 through which the molten metal flows by cenicetrifugal action from the Crucible 22 to the mold orflask 26 when bar l2.is rotated by motor M.

in accordance with the present invention, the liask or mold 26 ismounted for rotation about its longitudinal axis which extends radiallyof the axis of shaft 14, so that during the rotation of furnace 1d inthe centrifugal casting operation of the machine, the ask 26 can berotated about its own longitudinal axis whereby the molten metal whichflows into the flask by centrifugal force is distributed evenly andunder uniform pressure throughout the mold cavity, thereby greatlyimproving the uniform density of the casting in the mold.

The provision for mounting the liask 26 for rotation about its own axisand as a unit with the furnace 10 about the axis of shaft i4 comprises aflask holder 28 which is carried by a stub shaft or spindle 3l)journalled for rotation in a bracket 32 which is preferably providedwith a ball or other anti-friction bearing 34. Bracket 32 is mounted forsliding movement on bar 12 and for that purpose has a lower bifurcatedportion 36 which snugly engages the opposite sides of the bar and whichis provided with guide rollers 3S which engage the lower edge of saidbar. The flask holder 28 is held releasably, but firmly, in engagementwith the outer end of liask 26 by means of a tension spring 40 which issecured at one end 42 thereof to the bar l2 and which is secured Vat itsother end dd to the counterweight 46 which is adjustably positioned onthe rods i3 which are fixed to the slideable bracket 32.

The inner end of flask 26 is releasably secured to a plate 5t) which isfixed to and rotated by a gear 52. The detachable connection between theinner end of flask 26 and plate 50 is constituted, as here shown, bypins 54 which are fixed to the peripheral wall of said ask incircumferentially spaced relation and engage plate 50 in openings 56. Asbest shown in FIG. 2, the forward surface of fiask holder 28 is conicaland is preferably provided with a plurality of annular flat portions 29in axial spaced relation and of different circumferential dimensions forengagement by flasks of different diameters, respectively. Similarly,rotary driving plate Sli is provided with openings nearer the axis ofits rotation than openings 56 to receive the pins Se of the smallerflask.

Mechanism is provided for rotating plate 50 automatically in response tothe rotation of the furnace 16' for the casting operation. Saidmechanism comprises a gear 52 journalled for rotation on the hub 53which is fixed to and projects from the apertured end wall 6i) offurnace ill) through which the sprue of the Crucible projects into themold. Gear 52 is rotated automatically when bar 12 is rotated by motor Mfor the centrifugal casting operation of the machine. For this purposeand in accordance with the presently preferred form of this invention,an internal stationary gear 62 is fixed to the top of the housing '6d ofthe motor M and meshes with `a gear 66 for rotating a shaft 5S whichprojects through and is journalled for rotation in bar l2 (FGS. 2, 6 and7). The upper end of rotary shaft 6d is provided with a bevel gear '7dwhich meshes with a companion bevel gear 72 for rotating a shaft 7dmounted for rotation in bearings 76 and Til carried by bracket Sli fixedto the top of bar l2. Shaft 74 is provided with a gear 82 which mesheswith gear S2 for rotating said gear and thereby rotating flask 26 aboutits longitudinal axis.

It will be understood that the spring motor M is wound up by rotatingbar l2 by hand, when the electrical movable contact member 7l isretracted from engagement with the companion stationary contact device'71a by the finger piece 73 as described in the above mentioned patents.After the motor is wound, the contact member 7l is projected intoengagement with the contact device 71a to energize the heater winding(not shown) and to hold the furnace stationary until the metal in thefurnace becomes molten and the temperature of the molten metal is at thedesired value.

In the form of the invention illustrated in FIGS. 8 to 10, theconstruction is substantially the same as described above, except that asprocket gear 52a is used instead of the gear 52 and is rotated by asprocket chain 84 which is driven by a sprocket wheel 86 fixed to arotary shaft 88. Also, in this form of the invention, a stationary bevelgear 90 which is fixed to the top of the motor housing is used insteadof the internal stationary cylindrical gear 62 and said bevel gear 90meshes with a companion bevel gear 92 for driving shaft 88. It will beobserved that said shaft 88 is fixed to the bar 12 so that as said baris rotating during the centrifugal casting operation, shaft 88 isrotated and drives sprocket gear 52a which rotates the flask 26.

Referring to FIGS. 2, 11 and 12, it will be observed that the flask 26is provided with a recess 94 which is in communication with the outletend of the sprue 24 of the crucible when the flask is in posi-tion, andit will be observed that this recess 94 is wider at an intermediateportion thereof than at its inlet end. This lateral enlargement of theintermediate portion of recess 94 provides additional space to receivemolten metal from the Crucible of the furnace in order to obviate anytendency of molten metal to escape at the joint between the flask andthe plate 50. As illustrated by FIGS. 11 and l2, the recess 94 is formedby the integral projection 96 of the llexible auxiliary device 98 whichis formed of rubber or other suitable material. This auxiliary deviceincludes an inner integral rim 100 which fits within the opening in thebottom of the flask, as illustrated by FIG. ll, when the flask ispositioned on said auxiliary device for mounting the wax pattern 102 andfor providing the llask 26 with the refractory material 104 in which themold cavity is formed when the wax is removed by heat in the usual way.As here shown, the central part of the auxiliary device 98 is providedwit-h an opening 106 in which a rod 108 is removably positioned forsupporting the wax pattern 102 while the plaster or other refractorymaterial is poured into the llask around the pattern. Also, it will beunderstood that removable rod 108 which supports the wax pattern 102forms a sprue opening in communication with recess 94 and with the moldcavity, formed after the wax pattern is melted out, for the flow ofmolten metal into the mold cavity. The base of the auxiliary device 98is provided with recesses 110 to receive the projecting ends of theilask pins 54. Said base is also provided with an outer rim or flange112 which is engaged by the outer surface of flask 26, when the flask isof a larger size, and in such case, the pins 54, instead of being on theouter surface of the ask, are disposed on the inner surface thereof andthe same recesses 110 are to receive the pins of such larger flask.Thus, the auxiliary device 98 is designed to be used with flasks of twodifferent diameters, the flask of smaller diameter having the pins 54 onthe outside and the flask of larger diameter having said pins on theinside thereof. It will be understood that after the refractory plasterhardens, device 98, being flexible, may be readily removed from the endof the flask, and thereafter the wax may be melted out to form the moldcavity in the usual way.

While I have shown and described the preferred embodiment of myinvention including two different forms thereof, it will be understoodthat the invention may be embodied otherwise than as herein specificallyshown or described and that in the illustrated forms of the invention,certain changes in the details of construction and in the arrangement ofparts may be made without departing from the underlying idea orprinciples of this invention within the scope of the appended claims.

Having thus described my invention, what I claim and desire to secure byLetters Patent is: 1. yIn a centrifugal casting machine, a rotaryhorizontal bar mounted for rotation about a vertical axis, means forrotating said bar, said bar being manually operable for energizing saidrotating means for the casting operation, a furnace and a mold carriedby said bar at one side of said vertical axis, said mold being mountedadjacent to said furnace at one end thereof and in communicationtherewith at said one end so that said furnace and said mold arerotatable as a unit with said bar about said vertical axis for thetransfer of the molten material from the furnace to the mold for thecentrifugal casting operation, means mounting said mold for rotation inrelation to said furnace about an axis transverse to said vertical axis,and mechanism operatively connected to said mold for rotating said moldabout said transverse axis concurrently with the rotation of saidfurnace and mold as a unit about said vertical axis, said mechanismcomprising a stationary gear co-axial with said vertical axis andcompanion movable gearing carried by said bar operatively connectingsaid stationary gear to said mold, said companion movable gearing beingrotatable as a unit with said furnace and mold about said vertical axisand being operated by the rotation of said bar, whereby said barrotating means is operable to concurrently rotate said mold about saidvertical and transverse axes for the casting operation simultaneouslywith the rotation of said furnace and bar about said vertical axis, saidmovablel gearing including a gear mounted for rotation on said furnaceadjacent said one end of said mold and disposed between said furnace andsaid mold, said furnace mounted gear having an aperture positionedaxially thereof to permit flow therethrough of the molten metal fromsaid furnace to said mold for the casting operation.

2. A centrifugal casting machine according to claim 1, wherein saidstationary gear comprises an internal cylindrical gear, and a rotarygear is carried by said bar `and is in mesh with said stationary gearand is mounted on a vertical shaft which is journalled for rotation insaid bar, and said vertical shaft has a gear which is positioned abovesaid bar and is operatively connected to said gear on said furnace.

3. In a centrifugal casting machine, a rotary horizontal bar mounted forrotation about a vertical axis, spring motor means connected to said barfor the rotation thereof, said bar being manually operable forenergizing said spring motor means for the casting operation, a furnaceand a mold carried by said bar at one side of said vertical axis, saidmold being mounted adjacent to said furnace at one end thereof and incommunication therewith at said one end so that said furnace and saidmold are rotatable as a unit with said bar about said vertical axis forthe transfer of the molten material from the furnace to the mold for thecentrifugal casting operation, means mounting said mold for rotation inrelation to said furnace about an axis transverse to said vertical axis,and mechanism operatively connected to said mold for rotating said `moldabout said transverse axis concurrently with the rotation of saidfurnace and mold as a unit about said vertical axis, said mechanismcomprising a stationary gear co-axial with said vertical axis andcompanion movable gearing carried -by said bar operatively connectingsaid stationary gear to said mold, said companion movable gearing beingrotatable as a unit with said furnace and mold about said vertical axisand being operated by the rotation of said bar, whereby said springmotor means is operable to concurrently rotate said mold about saidvertical and transverse axes for the casting operation simultaneouslywith the rotation of said furnace Iand bar about said vertical axis,said movable gearing including a gear mounted for rotation on saidfurnace adjacent said one end of said mold and disposed between saidfurnace and said mold, said furnace mounted gear having an aperturepositioned axially thereof to permit flow therethrough of the moltenmetal from` said furnace to said mold for the casting operation.

(References on following page) 5 6 References Cited in the file of thispatent 2,433,065 Rubissow Dec. 23, 1947 UNITED STATES PATENTS 2,752,650Bosna July 3J 1956 1,496,429 Pollen June 3, 1924 FOREIGN PATENTS

